Catalogs (Objects)
You may have been asking yourself after spending a short time on this site...what are these “M” objects. I mentioned M13, M35, M81, M82, M104 and also listed NGC 3628. Where did they come up with these numbers and prefixes?
Let’s address the “M” objects first.
There was a man by the name of Charles Messier. He was a French astronomer who lived from 1730-1817. Without going into a great detail about his life, I would just say that his passion in astronomy was comets. As he became more proficient in the night sky he noticed other fuzzy objects that he thought might have been comets, but over time these objects did not move. To avoid confusion he began to label these objects and thus began what we now call “Messier Objects”.
On August 28, 1758 he observed a small patch in the constellation Taurus. Realizing it was not moving, he believed it to be nebula and not a comet. About a month later it turned out to be his first entry into what is now the Messier Catalog. He named it Messier 1 or M1 and later it was named the Crab Nebula.
Over the years that followed he continued to log other objects until he published his first catalog in 1774 which included 45 objects. From 1774 to 1780 he added more to the list which then totaled 68. His protege Pierre Mechain added more to the catalog until in 1787 there were 103 objects. Later astronomers added seven more believing that Messier himself had observed them. The present catalog now stands at 110 objects.
The Messier catalog not only contains nebulas but star clusters and galaxies as well. This catalog contains some of the most impressive objects in the Northern Hemisphere and it’s been labeled as the “greatest hits” of the night sky.
Once a year around March/April it’s possible, if conditions are favorable, to see all 110 objects in one night. Amateur astronomers call this night a “Messier Marathon” and there have been many people who have observed all 110 in one evening. There are certificates you can earn by observing various amounts in a designated period of time.
If you would like to know more about Charles Messier visit the web at www.seds.org/Messier.
What about “NGC”
Thousands of more objects have been observed and labeled since Charles Messier. They chose not to add any more to his catalog but rather started another catalog which is called the “New General Catalog” or NGC. There are thousands of objects in this catalog, many just as impressive as the “M” objects. Depending on the charts or maps you get many of the NGC objects will be listed along with the Messier objects.
There are many catalogs available with information on NGC and Messier objects but one of my favorites is the “skyatlas 2000.0 Companion” by Robert A. Strong and Roger W. Sinnott. I purchased mine at
sky and telescope.com along with the sky atlas maps. I find this book to be an excellent resource of information not only for my needs but also to share with others who may be just getting interested in astronomy.
There are other indexes and listings available but I believe this "skyatlas 2000.0 companion" with 2700 entries will keep you busy for a long time.